Encoding signals in communication systems often requires the application of many codes in which a plurality of codes are applied to a signal as a sequence of overlays to accomplish several objectives in conditioning the signals to meet diverse signal transmission and switching objectives. Some encoding examples may include spreading and overspreading applied to create a CDMA signal optimized for transmission channels. Other code processes include error correction, signal correlations or de-correlations, etc.
These multiplicity of code applications must frequently be handled by a plurality of processing stations located between an originating and a terminating station. Normally the signal must be decoded and recoded at each processing station. This represents a considerable processing effort at each such station which leads to overall signal transmission inefficiencies.
In other transmission processes (i.e. CDMA), the signals may be spread or despread in several stages of successive processing stations. These processes may or may not alter the overall spreading rate dependent on the spreading processes. Spreading applications having successive layers of spreading are performed sequentially and if the original signal is to be recovered in an intermediate processing station the despreading for recovery is in reverse sequence and subsequent respreading is performed in the exact same sequence as the original spreading operation at the transmitter. Again the processing required may be instituted even though the recovery of the original signal is not needed and significantly reduce transmission efficiencies.